Microbial Ecology of the Planetary Boundary Layer

Abstract

Aerobiology is a growing research area that covers the study of aerosols with a biological origin from the air that surrounds us to space through the different atmospheric layers. Bioaerosols have captured a growing importance in atmospheric process-related fields such as meteorology and atmospheric chemistry. The potential dissemination of pathogens and allergens through the air has raised public health concern and has highlighted the need for a better prediction of airborne microbial composition and dynamics. In this review, we focused on the sources and processes that most likely determine microbial community composition and dynamics in the air that directly surrounds us, the planetary boundary layer. Planetary boundary layer microbial communities are a mix of microbial cells that likely originate mainly from local source ecosystems (as opposed to distant sources). The adverse atmospheric conditions (i.e., UV radiation, desiccation, presence of radicals, etc.) might influence microbial survival and lead to the physical selection of the most resistant cells during aerosolization and/or aerial transport. Future work should further investigate how atmospheric chemicals and physics influence microbial survival and adaptation in order to be able to model the composition of planetary boundary layer microbial communities based on the surrounding landscapes and meteorology.

Microbiome Interconnectedness throughout Environments with Major Consequences for Healthy People and a Healthy Planet

“…Microorganisms are transported long distances by aeolian (wind) processes (51,52). Transport can be as autonomous bodies such as fungal spores, as cells adsorbed to the external and internal surfaces of mineral particles (dust), or in liquid microbodies (aerosols) (46,53). Both the extent of transport and the distance transported are likely to be affected by both the particle size of the dust, and cell body size of the microorganism (54).…”

Selection processes of Arctic seasonal glacier snowpack bacterial communities

“…Since snowflakes form in clouds before traveling through the atmosphere and depositing on terrestrial surfaces, snow is tightly coupled to the atmosphere [ 18 – 20 ]. Therefore, the snowpack provides an opportunity to investigate the involvement of atmospheric microorganisms that have been linked to cloud development, atmospheric chemistry, and microbial biogeography [ 21 , 22 ] in snow formation and their subsequent persistence in terrestrial snowpack communities. Microorganisms can serve as ice nucleation particles (INPs) that are required for snow crystal growth in clouds and are found in freshly fallen snow and other precipitation forms [ 23 – 26 ].…”

Biological Characterisation of Hailstones from Two Storms in South Brazil

“…Clouds, in some respects, can be extreme environments characterised by low pressure and pH, with a mixture of organic and inorganic components that are toxic to the living fraction of PBAPs [12,13]. Nevertheless, not only are bacteria and fungi found in such adverse cloud environments, but they impact cloud physicochemical properties and rain [1,14,15].…”

“…The inherent complexity in atmospheric community assembly depends utterly on land-cover and land-use patterns [21]. In addition, factors such as humidity and dispersal capacity are essential for PBAPs transportation, impacting on the atmospheric processes depending on them [6,13]. Although studies focusing on storm clouds have been carried out previously, there is a lack of studies investigating PBAPs' presence in hailstones.…”